The present invention relates generally to a torsion shock absorber device of the kind comprising two parts mounted for relative rotation with limited angular movability, and coupled by shock absorbing elastic means, the said angular movability being controlled by the said shock absorbing elastic means and also by friction between the said parts, this friction being arranged by axial elastic clamping, one of the said parts comprising a disc and the other part comprising two guide washers fastened together and disposed one on each side of the said disc, the disc and the guide washers having openings some of which serve to position the aforesaid elastic means.
The present invention relates more particularly, but not exclusively, to the case in which a torsion shock absorber device of this kind is provided for a clutch friction element, particularly for an automobile vehicle.
As is known, in the case of a clutch friction element of this kind one of the parts composing the said friction elements carries a friction disc which is provided around the periphery of each face with friction linings intended to be gripped between two plates which are rotationally fast with a shaft, (in practice the driving shaft), while the other of the said parts is fastened to a hub which is adapted to be engaged on another shaft, (in practice the driven shaft).
A clutch friction element of this kind makes it possible to achieve regulated transmission of a torque between that one of its component parts which is rotationally fast with the driving shaft and that one of its component parts which is rotationally fast with the driven shaft, that is to say to filter the vibrations, particularly acoustic vibrations, which may moreover be formed all along the kinematic chain in which the driving and driven shaft are interposed.
In the case of a small clutch friction element intended for transmitting low torque, its guide washers which assist the axial clamping may comply with the two conditions of being sufficiently strong in the circumferential direction to transmit this low torque and of being sufficiently flexible in the axial direction to effect the axial elastic gripping which adjusts the friction between the two parts of the torsion shock absorber device.
However, in the case of a clutch friction member which has to transmit a relatively substantial torque, which in turn implies considerable axial elastic gripping, the guide washers are too thick to be able to have sufficient flexibility in the axial direction, and in this case it is usual for the axial elastic gripping which adjusts the friction to be achieved by means of a relatively complex arrangement including, among other parts, a corrugated spring. Arrangements of this kind are generally satisfactory from the technical point of view, but they increase axial dimensions, sometimes to a prohibitive extent, and increase the cost price.
The present invention has as its object a torsion shock absorber device which makes it possible to retain extreme simplicity of construction together with small axial dimensions, and which is usable even when the torque to be transmitted is relatively high.